Collecting reservoir and method for recovering working medium in sorption devices

ABSTRACT

The invention relates to a sorption device, wherein working medium that escapes when inert gas flows out is collected in a collecting reservoir ( 1 ), and wherein said working medium can be returned from the collecting reservoir to a part of the sorption device that is different from the collecting reservoir. The invention further relates to a method for recovering working medium and the use of a collecting reservoir to collect working medium and return working medium to a sorption process.

PRIOR ART

Sorption devices, in particular sorption cooling machines, are knownfrom the prior art.

Materials and substances present in a sorption system can outgas or canfor example release gases as a result of a chemical conversion. Thesedisturbing gases or vapours prevent a rapid sorption process becausethey make the access of the vaporous working medium to the sorptionmedium difficult during adsorption or absorption, and prevent or makedifficult the access of the vaporous working medium to the condensationsurfaces during desorption, both of which result in an extreme slowingdown of the heating and/or refrigeration process. The consequence is asubstantial drop in performance of these sorption systems. What isreferred to here as disturbing gases are generally substances thatinfluence the access of the working medium vapours to the sorptionmedium and thus impede the sorption process (for example carbon dioxide,nitrogen etc.). The gases are also referred to as inert gases or foreigngases. These substances may be pre-sorbed in the sorption medium,released as a result of a chemical reaction, degassed from the availablehousing materials or enter via leaks in the system. In summary, thismeans that in such vacuum sorption devices there is in principle theproblem that either outgassing or leaks can lead to an increase inpressure and thus to a degradation of the function of the device.

The prior art describes various means for removing the inert gases fromthe system of the sorption machine. For example, DE 44 252 B4 disclosesa method wherein a binding agent is introduced into the sorptionmachine. In order to keep the system free of disturbing inert gas orvapour for the sorption process, so that only working medium vapour ispresent during the vapour phase, a binding agent is added to thesorption system. This binding agent has here the task of binding anyinert gases or vapours present or released in the sorption system andthus to extract them from the working medium vapour space. In doing so,it has to be capable of binding as much inert gas or vapour as isreleased in the sorption system by degassing or a chemical reaction ofthe substances and materials contained therein. Therefore, in ahermetically sealed sorption system, only a limited amount of inert gasor vapour can occur, and this is usually at the beginning of thesorption cycles. Within this period of time, the binding agent onlyneeds to bind this particular amount of inert gas. Suitable as bindingagents are in principle any substances that are capable of binding theinert gases or vapours occurring in a sorption system. However, thebinding agent should be able not to release the bound inert gas even inthe case of system-related temperature fluctuations. Since most bindingagents have a tendency to do so at high temperatures, the binding agentshould be positioned at a location where temperatures as low as possibleand only minor temperature fluctuations prevail. In a sorption system,the highest temperatures occur in the sorption agent container duringsorption as well as during desorption. According to DE 44 44 252 B4, thebinding agent is placed in a region where the comparatively lower systemtemperatures are present, e.g. in the condenser, the evaporator or inthe collecting reservoir.

Further, DE 103 10 748 B3 describes a method for removing inert gasesfrom a sorption machine. In this context, an intermediate phase isprovided in which, once foreign gases have been detected in the system(for example as a result of an increase in the internal pressure or as aresult of an insufficient condenser performance), a process is startedwhich removes these disturbing gases from the vacuum system. Initially,the heat dissipation from the condenser is prevented as completely aspossible. Thereafter, heat is for example supplied to the sorber via aburner. The working medium (preferably water), which is driven out ofthe sorption agent in the form of vapour, initially condenses at thecoldest location in the vacuum space and continuously heats the completevacuum space, which during normal operation is under a vacuum. In thecourse of this, the pressure rises in the system. If the system pressureexceeds the ambient pressure (as a rule an ambient pressure of 1013mbar, but other constellations are also possible), a discharge unit (forexample and preferably a valve) opens and allows the vaporous content toflow out into the ambient atmosphere. In a fashion, the vapour comingfrom the sorber therefore gradually “pushes” the foreign gases out. Inthe course of this, also part of the working medium normally gets lost.Once all the foreign gases have been removed from the system, thedischarge unit is closed.

EP 2 357 433 discloses a device that is connected to a sorption machine.Here, a cavity for buffering inert gas is connected in the region of theliquefier. The cavity has an inlet valve in the lower region thereof,and the inlet valve is always covered, on the cavity side, with liquidworking medium.

The prior art also discloses a process of removing inert gas, whereinthe inert gas collects in the condenser of a sorption machine, inparticular an adsorption machine or in a separate device (inert gascollection device). An inert gas collection device is also referred toas an inert gas trap or an inert gas collection device. This devicehaving inert gas and working medium is heated up to overpressure, andsubsequently water vapour and inert gas are blown off into theenvironment.

U.S. Pat. No. 3,555,849A describes an absorption machine, whereinnon-condensable gases are regularly removed from the system. Thisdocument deals with the problem that working medium gets lost as aresult of the process of inert gas removal. It is proposed to remove theinert gas via an adsorption process and to expel it only after that.This is supposed to prevent larger amounts of working medium fromflowing out with it.

Similar solutions are proposed in U.S. Pat. No. 3,592,017A, U.S. Pat.No. 5,806,322A and U.S. Pat. No. 5,209,074A.

The inert gas removal devices from the prior art have severaldisadvantages. Thus, the water vapour has to be blown off in acontrolled manner, and therefore moisture also collects in the system.As a result of this repeated process, the sorption cold machinegradually loses coolant (in particular water). DE 103 10748 describesdevices, but this problem is completely ignored. Here, an amount ofworking medium (e.g. coolant) that corresponds to the size of the systemand is geared to the lifetime of the system is provided during theproduction of the device. However, this increases the costs of thesystem and moreover leads to difficulties if the system is supposed tobe operated longer than originally planned.

Accordingly, it is the object of the present invention to provide adevice and a method for preventing loss of working medium and forovercoming the problems encountered in the prior art.

DESCRIPTION OF THE INVENTION

This object is achieved by means of the independent claims. Advantageousembodiments can be seen from the dependent claims.

In a first preferred embodiment, the invention relates to a sorptiondevice, comprising at least one collecting reservoir, a condenser, adesorber and a working medium, wherein the collecting reservoir isdirectly or indirectly connected to the condenser and wherein at leastone throttle element is provided between the collecting reservoir andthe condenser, wherein working medium is collected in the collectingreservoir, which escapes when inert gas flows out, and wherein thisworking medium can be returned from the collecting reservoir into partof the sorption device that is different from the collecting reservoir.

The wording “into part of the sorption device that is different from thecollecting reservoir” is meant to refer to the fact that the workingmedium is discharged from the collecting reservoir, however withoutleaving the sorption device.

Inert gas can here also be referred to as foreign gas.

A person skilled in the art knows which further components are containedin the sorption device. Preferably, an evaporator is also included.Moreover, an adsorber or an absorber is preferably included. Instead ofthe adsorber, however, the desorber may also be implemented as anadsorber-desorber unit. In terms of the invention, therefore, a desorbermay also act as an adsorber-desorber.

In terms of the invention, the condenser may also be a combinedevaporator/condenser unit.

The invention is based on a general rethinking. Conventional sorptiondevices or sorption units are systems that are sealed as far as possibleor are hermetically sealed. So far, experts have normally been tryingnot to allow any return flow into such a vacuum system. This is alsoevident from the solution approaches made so far, because the attemptsso far made in the prior art have been directed to freeing the inert gasas much as possible from working medium prior to the latter flowing out.This means that attempts have been made to keep the outflow of workingmedium as low as possible. So far, nobody has thought of returning theworking medium. Therefore, the invention pursues a completely novelapproach. The aim is no longer to control the loss of working mediumitself, but to recover “lost” working medium. The invention allows theworking medium to flow out into a region in which ambient pressureprevails (namely into a collecting reservoir). Subsequently, the workingmedium is returned from the area with ambient pressure back into thevacuum system. Such an approach has so far neither been disclosed norsuggested in the prior art.

As a result of this return, the many and complex solution approachesfrom the prior art, which address the problem of freeing the inert gasfrom working medium, become redundant.

The collecting reservoir is a simple and low-cost device that can alsobe retrospectively fitted to older sorption devices. In this context itis particularly advantageous if the preferred collecting reservoir canbe disassembled.

A great advantage of the invention is moreover that the sorption devicecan be filled, re-filled and/or evacuated via the collecting reservoir.

The collecting reservoir can be installed in any desired way and at anylocation, as long as the working medium can be completely returned.

The throttle element is preferably selected from the group comprisingvalves, straight-way valves, angle valves, Y-type valves, magneticvalves, check valves and/or float valves. The throttle element ispreferably integrated into a connection means and effects a localnarrowing of the flow cross section. Advantageously, different valves,which may be classified according to their geometrical form, may beintegrated into a throttle element. As a result of using a valve, theflow rates in the connection means can be accurately and precisely dosedby modifying the nominal diameter and also a secure sealing against theenvironment may be provided. The throttle elements can advantageously beactuated by hand, by a medium, automatically or electromagnetically.

It is particularly preferred if the throttle element is provided betweenthe collecting reservoir and the condenser and is a valve, a magneticvalve, a slide valve, a check valve, a capillary tube and/or a membrane.

It is preferred if the throttle element is provided with a controlbetween the condenser and the collecting reservoir, which opens thethrottle element as soon as a pressure that is higher than that in thecollecting reservoir occurs in the condenser. If the throttle element isimplemented as a float valve, then the weight of the float valve has tobe sufficiently great to ensure that an opening, on or against which itrests, is securely sealed. During the desorption phase, the float valveis lifted by the working medium vapour flowing into the collectingreservoir. The float valve may for example be manufactured from plastic,e.g. polypropylene.

It is preferred if a connection means connects the condenser with thecollecting reservoir. In this connection it is particularly preferred ifthe connection means is at least one tube or an outlet opening. The tubeis preferably connected to the condenser and the collecting reservoir inan interlocking or bonded manner. Interlocking connections arepreferably achieved by the interengagement of at least two connectionpartners. Interlocking connections comprise screws, rivets, pins orclamps. The tube can for example be connected to components of thesorption device and the collecting reservoir by means of screws orrivets and corresponding seals.

It is also possible to attach the connection means to the condenser andthe collecting reservoir by bonding means. Bonding connections are heldtogether by atomic or molecular forces. They are at the same timenon-releasable connections that can be released only by destruction.Bonded connections comprise soldering, welding or adhesion.

In terms of the invention, the working medium can preferably be a fluidor a coolant. Particularly preferred is the use of water as a workingmedium.

Particularly preferred is the sorption device, which moreover includesan inert gas trap and the collecting reservoir can be connected to thecondenser via this inert gas trap. However, it is also preferred thatthe collecting reservoir is part of the inert gas trap. This means thatthe collecting reservoir does not necessarily have to be a separatecomponent.

This is the described indirect connection of the collecting reservoirand the condenser. This indirect connection is preferably realised bythe inert gas trap. Therefore, the collecting reservoir is connected tothe condenser via the inert gas trap. In this embodiment, at least onedescribed connection means is located between the collecting reservoirand the inert gas trap and at least one connection means is locatedbetween the condenser and the inert gas trap.

The above-described preferred embodiments of throttle elements andconnections are also preferred for this variant of the invention.

This embodiment is particularly advantageous because the advantages ofthe inert gas trap are combined with the advantages of the returnthrough the collecting reservoir. As a result of the inert gas trap,which is preferably an inert gas trap according to WO 2012/069048, novacuum pump, binding substance or any noteworthy use of energy is neededfor the evacuation of the foreign gases. The evacuation of the foreigngases can be carried out during the ongoing, continuous operation of thesorption device. However, it may also be advantageous to collect theforeign gases in the inert gas trap, until a certain overall pressure ispresent in the reservoir, and only then to remove the gases from thereservoir. As a result of the achieved self-evacuation of the machine,maintenance requirements can be greatly reduced. The disclosure ofWO2012069048 is included in the present application.

What is also preferred is the sorption device, wherein a first throttleelement is provided between the inert gas trap and the collectingreservoir and a second throttle element is provided between thecondenser and the inert gas trap. This embodiment is preferred becauseboth the inflow of the inert gas into the trap and the outflow into thecollecting reservoir can be controlled.

What is particularly preferred is if the throttle element that isprovided between the collecting reservoir and the inert gas trap is avalve, a magnetic valve, a slide valve, a check valve, a capillary tubeand/or a membrane. This embodiment is advantageous because thesethrottle elements realise an effective seal.

It is also preferred that the inert gas trap can be heated. Thus, byheating the inert gas trap, the pressure inside the trap is increased.The pressure reached will remain in the vacuum range. This isadvantageous because the amount of air taken in is in particular afunction of the pressure differential between the sorption device or theinert gas trap and the environment. If the pressure achieved remains inthe vacuum range, the pressure differential is substantially reduced.

What is further preferred is the sorption device, with the collectingreservoir comprising internal baffle plates. This is particularlyadvantageous in order to achieve a condensation of vaporous workingmedia in the collecting reservoir. As a result of the baffle plates, thevapour of the working medium has a long and indirect path to theoutside. In addition, the vapour has to flow through the alreadycollected liquid. What is also preferred is a different type oftechnical means for separating the drops entrained in the flow. A personskilled in the art will know other possibilities for separating dropsfrom the vapour, without themselves exercising inventive skill.

In terms of the invention, a sorption device may be an adsorptionmachine, in particular an adsorption cooling machine or an adsorptionheat pump. In terms of the invention, a sorption device may also be anabsorption machine. The problem of inert gas removal and the associatedloss of working medium is a principal problem of sorption processes.Therefore, the reservoir can advantageously be used both for adsorptionand for absorption systems. It was completely surprising that thecollecting reservoir can be universally used and can be adapted todifferent system configurations. Advantageously, the collectingreservoir can be used for single-chamber systems, but also for systemswith two or more chambers. Moreover, it can be simply and quicklyadapted to other types of sorption machines. To this end, the machinessubstantially don't need any apparatus-related modifications. In termsof the invention, the system configuration preferably refers to theconfiguration of the sorption device, i.e. for example the internalhydraulic wiring of the components of the sorption device, the internalcoolant-side wiring of the components or the modified basic structure ofthe sorption device (i.e. the number of adsorbers, the operation of theevaporator, of the condenser etc.).

The adsorption cooling machine comprises at least an adsorber and adesorber and/or an adsorber/desorber unit, an evaporator, a condenserand/or a combined evaporator/condenser unit, which are accommodated in acommon container or in separate containers, which are then connected toeach other via pipes or the like for the flow of coolant. The advantageof the sorption machines compared to conventional heat pump technologylies in the fact that the process of adsorption/desorption is carriedout solely by tempering the sorption agent. Thus, the container of theadsorption machine can be sealed in a hermetical and gas-tight manner.The use of for example water as a coolant means that the adsorptioncooling machine preferably operates in the vacuum range.

The adsorption taking place in an adsorption machine describes aphysical process, wherein a gaseous working medium, preferably a coolant(for example water vapour), accumulates on a solid. The desorption ofthe coolant, i.e. the release of the coolant from the solid, in turnrequires energy. In an adsorption cooling machine, the coolant, which atlow temperatures and low pressures takes up heat and at highertemperatures and higher pressures gives off heat, is selected such thatthe adsorption or desorption is accompanied by a change of state ofaggregation. As adsorption agents, the prior art describes substancesthat have fine pores and therefore have a very large inner surface.Advantageous materials are active carbon, zeolites, aluminium oxide orsilica gel, aluminium phosphates, silica aluminium phosphates, metalsilica aluminium phosphates, mesostructure silicates, organometallicbackbones and/or microporous material, comprising microporous polymers.The adsorption material can advantageously be applied in different ways,which means by filling, adhesion and/or crystallisation. By way of thesedifferent types of application, the adsorption machine can be adapted tovarious requirements. Thus, the machine can be adapted to its locationor to the coolant. Moreover, the layer thickness of the adsorptionmaterial is a crucial factor for the performance of the adsorptionmachine.

The collecting reservoir is preferably made from metal and/or plastic.It has been found that as a result of this, a low-cost collectingreservoir for collecting working medium can be provided, which can alsowithstand high and fluctuating pressures and temperatures.

The collecting reservoir can here be connected to an existing sorptionunit. The collecting reservoir will preferably be connected to an inertgas trap (also referred to as a trap). However, the collecting reservoirmay also be part of the sorption device or of a vacuum, wherein thispart is divided off for example by a partition.

The size of the collecting reservoir is not crucial for its function andonly determines the frequency of the emptying process.

The shape of the collecting reservoir is preferably selected such thatthe working medium (e.g. water) that has flowed in can completely flowback. For example, a funnel-shaped form is preferred. It may beadvantageous if the container is shaped to be conical, and experimentshave shown that other shapes of the container are also functional andmay therefore be used.

It is particularly preferred if the collecting reservoir has an opening.The advantage is that this ensures the pressure to be balanced with theambient air. Thus, no positive pressure is generated if the inert gaswith working medium flows into the collecting reservoir and no vacuumpressure is generated, if the condensate is sucked or guided back. As aresult of the opening, the pressure in the collecting reservoir willalways be maintained at an ambient pressure level.

In this connection it is preferred if the opening is kept as small aspossible. In this way it is ensured that the entire working medium canbe returned from the collecting reservoir. This means that the onlyworking medium losses would be as a result of the evaporation from thecollecting reservoir into the environment. This is minimised orprevented by providing a correspondingly very small opening to theenvironment.

It is particularly preferred if the working medium is returned in aliquid form. The vapour of the working medium advantageously condenseson the inner surface of the collecting reservoir. In order to supportcondensation or to enforce it, an improved discharge of the condensationheat may be prudent. Advantageously, this is realised as follows:

-   -   by cooling fins (passive cooling, natural convection) and/or    -   by a fan (active cooling, forced convection) and/or    -   by a connection to a cold source (compression or sorption        cooling machine, Peltier element, but especially also to the        evaporator of the sorption device or by evaporation cooling        within the inert gas trap) and/or    -   by increasing the thermal mass of the collecting reservoir.

Moreover it is preferred that the sorption device comprises severalcollecting reservoirs which are disposed one after the other. Thus, theinvention can also be implemented in several stages, so that a pluralityof collecting reservoirs are connected one after the other or aplurality of inert gas traps are connected in series or parallel withone or more collecting reservoirs. This embodiment allows a particularlyeffective removal of the inert gases, at the same time with almostcomplete recovery of the working medium exiting with it.

In a further preferred embodiment, the invention relates to a method forrecovering working medium with a sorption process of a describedsorption device, wherein exited working medium, which has escaped duringthe removal of inert gases, is collected in a collecting reservoir andis returned from the collecting reservoir to a different part of thesorption device.

It is preferred here if the collecting reservoir is under ambientpressure. In this way it is ensured that the inert gas can escape via anopening in the collecting reservoir.

Preferably, the method comprises the following steps:

-   -   a. introducing a vaporous working medium from the desorber or        the desorber unit into the condenser, wherein the working medium        at least partially condenses in the condenser and the inert gas        collects in the condenser,    -   b. increasing the pressure in the condenser, preferably by        heating,    -   c. opening a throttle element provided between the condenser and        the collecting reservoir, so that inert gas and working medium        flow from the condenser into the collecting reservoir,    -   d. collecting the working medium in the collecting reservoir,    -   e. returning the working medium into a part of the sorption        device that is different from the collecting reservoir.

In the prior art, the working medium with the inert gas would flow outinto the environment. The usual objective was to minimise the loss ofworking medium, by ensuring that as little working medium as possibleflows out with the inert gas. However, the invention solves this problemin a different way. Here it is preferred that working medium flows out,because it is collected in the collecting reservoir. As long as it isensured that the working medium is returned, the system will not loseany working medium.

As a result of the heating of the condenser in step b, the pressure isincreased, so that the inert gas can flow out into the collectingreservoir once the throttle element has been opened.

If a sorption device with an inert gas trap is used, the methodpreferably comprises the following steps:

-   -   (i) cooling the inert gas trap using a cooling element to a        temperature that is lower, the same or similar to that of the        condenser,    -   (ii) introducing a vaporous working medium from the desorber or        the desorber unit into the condenser, wherein the working medium        in the condenser at least partially condenses and the inert gas        collects in the condenser,    -   (iii) opening the throttle element provided between the        condenser and the inert gas trap, so that inert gas and vaporous        working medium flow through the condenser into the inert gas        trap,    -   (iv) heating the inert gas trap,    -   (v) opening the throttle element provided between the inert gas        trap and the collecting reservoir, through which throttle        element the inert gas and the working medium flow out from the        inert gas trap into the collecting reservoir,    -   (vi) collecting the working medium in the collecting reservoir,    -   (vii) returning the working medium into a part of the sorption        device that is different from the collecting reservoir.

The steps are substantially similar. However, the inert gas is hereinitially guided into the inert gas trap. In this trap, the pressurewill then be increased by heating, so that the inert gas can flow out ofthe collecting reservoir when the throttle element is opened.

Preferably, the working medium is passed from the collecting reservoirback into the inert gas trap or the condenser. The return can be carriedout by return suction, for example by means of vacuum pressure.

In both cases the essential method steps can be depicted as follows:

Working medium flows out of the inert gas trap or the condenser. Thisworking medium flowing out may be present either in the form of drops oras vapour. These drops or the vapour will be collected by the collectingreservoir, where the vapour condenses. After a certain amount of time,the working medium is guided back into the sorption device. The returnpreferably takes place when a certain amount of working medium has beenreached in the collecting reservoir. This can be carried out e.g. insuch a way that the amount of working medium present in the collectingreservoir is measured or the return is carried out in certain timeintervals (or cycles), which may be synchronised with the operating modeof the inert gas trap.

In this collecting reservoir, when the inert gas flows out, the workingmedium (preferably coolant, particularly preferably water) thatautomatically flows out with it is collected. The working medium may becollected in the form of drops or vapour, and this vapour is thencondensed in the collecting reservoir. In a second step, the water isthen returned into the sorption system.

During the return, it is possible or even very likely that also airand/or inert gas is sucked or passed into the system, above all into thecondenser or into the inert gas trap. However, this is notdisadvantageous because the inert gas will be discharged more often thanthe working medium is returned. For example, an outflow of inert gas cantake place ten times, and subsequently a return of working medium cantake place, so that a ninefold “net outflow” of inert gas will havetaken place.

In this way, the working medium will be recovered from a plurality ofinert gas removal procedures. The preferred collecting reservoir iscompatible with various sorption machines known from the prior art andcan be universally used. The sucked air can either be directly removedafter the return of the working medium using the traditional method ormay remain in the system and may in particular gradually be removedtogether with the newly developing inert gas. The latter possibilitypreferably only applies in a case when the sucked air is minimal and theratio between removed inert gas and sucked air is positive.

The amount of sucked air is in particular a function of the pressuredifferential between the part of the sorption device, into which theworking medium is returned (e.g. the condenser or the inert gas trap)and the ambient air. At room temperature, the pressure of the inert gastrap will e.g. be approx. 50 mbar, whereas ambient pressure is 1000mbar. A pressure differential of 950 mbar will lead to the workingmedium being sucked out of the collecting reservoir when the throttleelement is opened. However, in the case of this relatively high pressuredifferential, a large amount of air will be sucked as well.

It is therefore preferred if the part of the sorption device, into whichthe working medium is to flow, i.e. for example the inert gas trap, isheated. However, in this case it has to be considered that it isadvantageous that a certain amount of vacuum pressure still remains, sothat the working medium can be returned as a result of the vacuumpressure. However, also other return methods are conceivable.

It has proved to be particularly advantageous to heat the part of thesorption device, into which the working medium is returned, which meansfor example the inert gas trap, to 50° C. to 90° C., particularlypreferably to 80° C. As a result, the pressure rises to approx. 900mbar. This means that the pressure differential with the ambientpressure will only be approx. 100 mbar instead of 950 mbar.

It is particularly preferred if the part of the sorption device, intowhich the working medium is returned, which means for example the inertgas trap or the condenser, is provided with a pressure sensor. Thissensor detects the pressure increase as a result of the opening of thethrottle element. If pressure compensation has taken place, the workingmedium has been returned either completely or almost completely. Thisembodiment is particularly advantageous, because it can be ascertainedin a simple manner when the return has been completed.

In particular, a collecting reservoir or an area of the inert gas trapfor the working medium, in particular the coolant, is provided, and thisis connected to an inert gas trap or the system of the sorption machine,preferably the adsorption machine and particularly preferably theadsorption cooling machine.

In a further preferred embodiment the invention relates to the use ofthe described collecting reservoirs for collecting and returning workingmedium in a sorption process, wherein the collecting reservoir ismounted on a sorption unit and wherein the working medium flows, duringthe removal of inert gas, from the sorption unit into the collectingreservoir, and the working medium flowing out is returned into thesorption unit.

The term sorption unit preferably refers to a sorption device without acollecting reservoir. A person skilled in the art will know whichcomponents have to be included in such a sorption unit in order to beable to carry out a sorption process.

One advantage of the invention is that the collecting reservoir can herebe connected to an existing sorption unit. The collecting reservoir ispreferably connected to an inert gas trap.

The collecting reservoir is a simple and low-cost device, which can alsobe retrofitted into older sorption units. It is here particularlyadvantageous if the preferred collecting reservoir can be demounted.

Particularly preferred is the use of the collecting reservoir where thecollecting reservoir is connected to an adsorption cooling machine. Theuse of such sorption devices has proved to be particularly advantageous,because in this way large amounts of working medium can be saved.

FIGURES

The invention will be explained by means of exemplary figures, howeverit is not limited thereto, because the embodiment of the collectingreservoir and of the system has only been shown in a schematic form.Above all, the figures only show the variants of a separated collectingreservoir on a separated inert gas trap. However, one or both elementsmay also be installed in the sorption device. Moreover, the figures donot show the entire sorption device. In the figures:

FIG. 1 shows a preferred collecting reservoir 1 that is connected to athrottle element 2;

FIG. 2 shows a preferred collecting reservoir 1 that is connected to acondenser 3 via a throttle element 2;

FIG. 3 shows a preferred collecting reservoir 1 that is connected to acondenser 3 via an inert gas trap 4. In this connection, a throttleelement 2 is provided between the collecting reservoir 1 and the inertgas trap 4 and a further throttle element 2 is located between the inertgas trap 4 and the condenser 3.

LIST OF REFERENCE NUMERALS

1 Collecting reservoir

2 Throttle element

3 Condenser

4 Inert gas trap

1. A sorption device comprising at least one collecting reservoir, acondenser, a desorber and a working medium, wherein the at least onecollecting reservoir is directly or indirectly connected to thecondenser, and wherein at least one throttle element is provided betweenthe collecting reservoir and the condenser, wherein the sorption deviceis configured so that working medium that escapes during the flowing outof inert gas is collected in the collecting reservoir, and said workingmedium can be returned from the collecting reservoir into a part of thesorption device that is different from the collecting reservoir.
 2. Thesorption device as claimed in claim 1, wherein the sorption devicemoreover comprises an inert gas trap and the collecting reservoir isconnected to the condenser via said inert gas trap.
 3. The sorptiondevice as claimed in claim 2, wherein a first throttle element isprovided between the inert gas trap and the collecting reservoir and asecond throttle element is provided between the condenser and the inertgas trap.
 4. The sorption device as claimed in claim 1, wherein thecollecting reservoir comprises internal baffle plates.
 5. The sorptiondevice as claimed in claim 1, wherein the sorption device is anadsorption device.
 6. The sorption device as claimed in claim 1, whereinthe collecting reservoir has at least one opening.
 7. The sorptiondevice as claimed in claim 1, wherein the sorption device comprises aplurality of collecting reservoirs arranged in a row.
 8. The sorptiondevice as claimed in claim 1, wherein the collecting reservoir is madefrom metal and/or plastic.
 9. The sorption device as claimed in claim 1,wherein the collecting reservoir comprises a coolant source and/orcooling fins.
 10. A method for recovering working medium in a sorptionprocess of a sorption device as claimed in claim 1, wherein exitedworking medium that has escaped during the removal of inert gases iscollected in the collecting reservoir and is returned from thecollecting reservoir into a part of the sorption device that isdifferent from the collecting reservoir.
 11. The method as claimed inclaim 10, comprising the following steps: a. introducing a vaporousworking medium from the desorber into the condenser, wherein the workingmedium at least partially condenses in the condenser and the inert gascollects in the condenser, b. increasing pressure in the condenser, c.opening a throttle element provided between the condenser and thecollecting reservoir, wherein the inert gas and the working medium flowfrom the condenser into the collecting reservoir, d. collecting theworking medium in the collecting reservoir, and e. returning the workingmedium into a part of the sorption device that is different from thecollecting reservoir.
 12. The method as claimed in claim 10, wherein thecollecting reservoir is connected to the condenser via an inert gastrap, and wherein the method comprises: (i) cooling the inert gas trapusing a cooling element to a temperature that is lower, the same orsimilar to that of the condenser, (ii) introducing a vaporous workingmedium from the desorber or a desorber unit into the condenser, whereinthe working medium at least partially condenses in the condenser and theinert gas collects in the condenser, (iii) opening a throttle elementprovided between the condenser and the inert gas trap, wherein the inertgas and vaporous working medium flow from the condenser into the inertgas trap, (iv) heating the inert gas trap, (v) opening a throttleelement provided between the inert gas trap and the collectingreservoir, through which the inert gas and the working medium flow outfrom the inert gas trap into the collecting reservoir, (vi) collectingthe working medium in the collecting reservoir, and (vii) returning theworking medium into a part of the sorption device that is different fromthe collecting reservoir.
 13. A method for collecting and returningworking medium in a sorption process, wherein the collecting reservoiris attached to a sorption unit and wherein the working medium flows,during the removal of inert gas from a sorption unit, into a collectingreservoir, and wherein the working medium that flowed out is returnedinto the sorption unit.
 14. The method of claim 13, wherein the workingmedium is returned in a liquid form.
 15. The method of claim 13, whereinthe working medium condenses in the collecting reservoir.
 16. The methodof claim 13, wherein the collecting reservoir is connected to an inertgas trap of the sorption unit.
 17. The method of claim 13, wherein theworking medium is sucked back by vacuum pressure.
 18. The method ofclaim 5, wherein the sorption device is an adsorption cooling machine.19. The method of claim 11, wherein the pressure in the condenser isincreased by heating.